KCU-04 CAN Bus J1939 Decoder Module
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SECTION 1 : INTRODUCTION
KCU-04 CAN Bus J1939 Decoder Module. Is an
optional add-on device for the Kutai Electronics
generator control units GCU-3000, (More
compatible Kutai Electronics generator controller
will be available at a later time) to decode CAN Bus
J1939 digital signals from new generation engines
and enabling generator controllers to maximum
protections and operation.
The KCU-04 helps to eliminate the needs for
temperature, pressure and speed (MPU) sensors in
a digital controlled system. The J1939 protocol from
the CAN bus network are interpreted instantly and
pass onto the generator controller.
CAN Bus Protocol：SAE-J1939
CAN Bus J1939 decode item：
● Engine coolant temperature
Range：-40 ~ 210°C (Once per 1.0 Second)
● Engine oil Pressure
Range：0 ~ 1000kPa (Once per 0.5 Second)
● Engine Speed
Range：0 ~ 8031RPM (Once per 0.5 Second))
● Warning Message List：
Engine over Speed
Engine low Speed
Engine low oil pressure
High coolant temperature
Low fuel level
Low battery voltage
Other warning message (Once per 1.0 Second)
SECTION 2 : DIMENSION
KCU-04
STATUS
KCU-04
CAN-H
CAN-L
Shield
J1939
Front Rear
SECTION 3 : INSTALLATION
Disconnect controller power source and follow the
below illustrations to complete the installation of
KCU-04.
Step 1 ：Remove slot cover from the back of
controller.
Step 2：Insert KCU-04 into the designated slot.
KCU-04 CAN Bus J1939 Decoder Module
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Step 3：Tighten the screw.
Step 4：Connect to CAN Bus network. The CAN Bus
transmitting device and the KCU-04 connection
must follow CAN-High connect to CAN-H, CAN-Low
connect to CAN-L and shielded line connect to
Shield.
Step 5：After powering up the controller, enter the
system setting to select whether to retrieve
information through KCU-04 or not.
Currently the KCU-04 only support GCU-3000
generator controller. Listed below are the related
settings. For details information, please refer to the
controller user manual.
GCU-3000
ITEM
DESCRIPTION
21
Equipped with oil pressure sender
00 No
01 Yes
02 KCU-04
Note：If KCU-04 is disabled from system setting, the
coolant temperature, oil pressure and engine speed
(Frequency) values must be obtain by the sensors
installed.
SECTION 4 : OPERATION
For more information on KCU-04 Data link status
LED indicator, please reference from chapter 5.
It is strongly suggested to use shielded dual-core
braided harness for CAN Bus wiring connection with
shielded grounding harness on one side.
CAN Bus Network connection example：
KCU-04 CAN Bus J1939 Decoder Module
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SECTION 5 : STATUS INDICATOR & TROUBLESHOOTINGS
5.1 Through the KCU-04 LED status indicator user can understand the current operating
status
STATUS
DESCRIPTION
KCU-04 communicating with Controller at link status
KCU-04 disconnect with CAN Bus & can't decode J1939 information
KCU-04 communicating with Controller in normal
5.2 Trouble shootings
STATUS
CAUSE OF FAILURE
TROUBLESHOOTING
CAN Bus J1939
Contact the nearest dealer. Check controller version if firmware
to support KCU-04.
CAN Bus J1939
1. Check CAN Bus J1939 communication if normal.
2. Check for correctly connected CAN Bus network.
SECTION 6 : J1939 NETWORK TOPOLOGY
SAE-J1939-11 protocol document defines the J1939 network topology and related provisions. For example
from the following illustration, the number of ECU controller (n) is based and limited to the length of the main
network. In a 40 meter network, the maximum number of nodes (ECUs) is 10 and if the network within 10
meters in length then maximum number of nodes (ECUs) is 30.
I
ECU
1ECU
2ECU
n-1 ECU
n
dL
RLRL
J1939 Network Topology
● Network to Node ECU Distance I：<1m
● Node to Node ECU Distance d：0.1m~40m
● Network Distance L：<40m
● Terminating Resistor RL：Standard 120Ω, 110Ω~130Ω (400mW)
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